1. Field
The technology of the present application relates generally to endotracheal tubes with electrodes to facilitate nerve monitoring, and more specifically, to an endotracheal tube that includes an electrode that is selectively positional along a length of the tube and capable of being fixed after positioning of the tube to facilitate monitoring of the laryngeal nerve.
2. Background
The recurrent or inferior laryngeal nerve (generically referred to as laryngeal nerve herein) provides connection between the brain and the larynx. The laryngeal nerve provides motor function and sensation to allow, for example, speech. Damage to the laryngeal nerve may result in changes to speech patterns, pitch, tone, or even muteness in extreme cases.
Referring to FIG. 1A, the left and right laryngeal nerves 1(L), 1(R) branches from the associated left and right vagus nerves 2(L), 2(R) and descends through the neck 3. The left laryngeal nerve 1(L) extends under the aorta 4 and rises up the neck between the trachea 5 and esophagus 6. The right laryngeal nerve 1(R) extends around the right subclavian 7 artery and rises up the neck between the trachea 5 and esophagus 6.
Due to its location and length, the laryngeal nerve 1(L), 1(R) is susceptible to damage during surgical procedures in the neck. Laryngeal nerve paralysis is most associated with thyroid and related surgeries, but is possible during other procedures around the neck, such as, for example, surgery associated with the cervical spine.
Referring to FIG. 1B, the anatomy associated with the larynx 7 is provided. The larynx is generally found anterior to the neck approximate cervical spine vertebrae C3-C6. The laryngeal nerves extend along the trachea 5 to the larynx. The muscles of the larynx are generally innervated by the recurrent laryngeal nerve 1(L) and 1(R). The cricothyroid muscles 8, however, are innervated by the superior laryngeal nerve 9, of which only one portion is shown in FIG. 1B.
Because damage is possible during surgery, many surgical procedures monitor the laryngeal nerves 1(L), 1(R), and 9, and possibly other nerves, during the surgery to alert a surgeon to damage or potential damage to the nerve as well as to help locate the nerve intraoperatively. Generally, devices having electrodes are used to intraoperatively monitor the laryngeal nerve. Some of these devices include devices inserted into the upper pharynx, endotracheal tubes with one or more fixed electrodes, and surface electrodes attached to the tracheal tube. None of these solutions are perfect solutions and each may have one or more drawbacks. For example, endotracheal tubes with one or more fixed electrodes are generally designed for typical anatomy and the electrode is not optimally placed for any particular surgical patient. Thus, against this background, it would be desirous to provide an endotracheal tube that would allow an electrode to be selectively placed and fixed at a location that optimized the conductivity between the electrode and the laryngeal muscles innervated by the laryngeal nerve.